Image sensor and image capture device

Abstract

In one embodiment of the present invention, an image capture device includes an image sensor 10 that includes: a photosensitive cell array 12 in which a plurality of photosensitive cells are arranged on an image capturing plane; a polarizer array 14 in which a plurality of unit structures, each including N polarizers (where N is an integer that is equal to or greater than two) that have mutually different polarization transmission axis directions, are arranged two-dimensionally and which is arranged so that light that has been transmitted through each polarizer is incident on its associated photosensitive cell; a circuit for reading a pixel signal from the photosensitive cell array 12 ; and a shifter 16 for shifting the polarizer array 14 with respect to the photosensitive cell array 12 parallel to the image capturing plane.

1 . An image sensor comprising:
 a photosensitive cell array in which a plurality of photosensitive cells are arranged on an image capturing plane;   a polarizer array in which a plurality of unit structures, each including N polarizers (where N is an integer that is equal to or greater than two) that have mutually different polarization transmission axis directions, are arranged two-dimensionally, the polarizer array being configured to allow light that is transmitted through each said polarizer to be incident on its associated photosensitive cell;   a circuit configured to read a pixel signal from the photosensitive cell array; and   an actuator configured to shift the polarizer array with respect to the photosensitive cell array parallel to the image capturing plane.   
     
     
         2 . The image sensor of  claim 1 , wherein when an image is being captured, the actuator shifts the polarizer array by a distance that does not exceed the size of the unit structure. 
     
     
         3 . The image sensor of  claim 1 , wherein when a stored electric charge signal is read from the entire photosensitive cell array, the actuator shifts the polarizer array on a pixel-by-pixel basis, thereby changing the polarization direction of light that is going to be incident on each said photosensitive cell. 
     
     
         4 . The image sensor of  claim 1 , wherein the image sensor is configured to perform:
 making light that has been transmitted through one of the N polarizers incident on each said photosensitive cell; and   shifting the polarizer array on a pixel-by-pixel basis and then making light that has been transmitted through another one of the N polarizers incident on the photosensitive cell.   
     
     
         5 . The image sensor of  claim 1 , wherein the actuator includes a first actuator portion configured to shift the polarizer array in a first direction on a pixel-by-pixel basis and a second actuator portion configured to shift the polarizer array in a second direction on a pixel-by-pixel basis, the second direction being perpendicular to the first direction, and
 wherein the actuator is configured to shift the polarizer array periodically and two-dimensionally on the image capturing plane.   
     
     
         6 . The image sensor of  claim 1 , wherein N is equal to or greater than three. 
     
     
         7 . The image sensor of  claim 1 , wherein the actuator is configured to move the polarizer array periodically and linearly on the image capturing plane. 
     
     
         8 . The image sensor of  claim 1 , wherein the arrangement pitch of the polarizers in the polarizer array equals to the arrangement pitch of the photosensitive cells in the photosensitive cell array. 
     
     
         9 . The image sensor of  claim 1 , wherein each of the unit structures includes four polarizers, the polarization transmission axis directions of the four polarizers being different from each other by 45 degrees. 
     
     
         10 . The image sensor of  claim 1 , wherein each of the unit structures includes three polarizers, the polarization transmission axis directions of the three polarizers are different from each other by 60 degrees. 
     
     
         11 . An image capture device comprising:
 an image sensor that includes a photosensitive cell array in which a plurality of photosensitive cells are arranged on an image capturing plane, a polarizer array in which a plurality of unit structures, each including N polarizers (where N is an integer that is equal to or greater than two) that have mutually different polarization transmission axis directions, are arranged two-dimensionally and which is arranged so that light that is transmitted through each said polarizer is incident on its associated photosensitive cell, and an actuator configured to shift the polarizer array with respect to the photosensitive cell array parallel to the image capturing plane;   a driver configured to drive the actuator; and   a shooting lens configured to produce an image on the image sensor.   
     
     
         12 . The image sensor of  claim 11 , wherein when a stored electric charge signal is read from the entire photosensitive cell array, the actuator shifts the polarizer array on a pixel-by-pixel basis, thereby changing the polarization direction of light that is going to be incident on each said photosensitive cell and obtaining luminance values of light rays that have been incident on respective photosensitive cells with mutually different polarization directions.